SAW devices are important components in RF circuits, especially in wireless communication devices. SAW devices are particularly important as delay elements. They provide low-velocity, non-dispersive propagation with low attenuation up to microwave frequencies and a propagation path which is accessible at a substrate surface.
While conventional SAW devices are not readily integrated into silicon microelectronic circuits, applicants' above-referenced U.S. application Ser. No. 09/137,431 describes magnetostrictive SAW devices which can be fabricated on silicon substrates. These devices can be integrated with microelectronic circuits useful in wireless communications.
In essence, a magnetostrictive SAW device comprises a substrate, a film of an appropriate magnetostrictive material disposed on the substrate, an input transducer for generating horizontally polarized shear waves along the film and an output transducer for receiving the shear waves. The substrate can comprise silicon and include one or more microelectronic circuit elements interconnected with the magnetostrictive SAW device. The transducers are typically serpentine (meander-type) electrodes.
The present invention provides devices of this type with improved transducer structures for enhanced performance.